- Ni-Catalyzed Enantioselective Benzylation of Secondary Phosphine Oxide
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A nickel-catalyzed benzylic substitution of secondary phosphine oxide was described, affording the dialkylated P-stereogenic tertiary phosphine oxides with high to excellent enantioselectivities. The reaction was performed under mild conditions with commercially available benzyl chlorides and bench stable secondary phosphine oxides, exhibiting broad functional group tolerance. It represented a practical example for the preparation of P-stereogenic phosphine compounds.
- Cai, Wen-Qiang,Wei, Qi,Zhang, Qing-Wei
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supporting information
p. 1258 - 1262
(2022/02/14)
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- Cobalt-Catalysed Asymmetric Addition and Alkylation of Secondary Phosphine Oxides for the Synthesis of P-Stereogenic Compounds
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The catalytic asymmetric synthesis of P-chiral phosphorus compounds is an important way to construct P-chiral ligands. Herein, we report a new strategy that adopts the pyridinyl moiety as the coordinating group in the cobalt-catalysed asymmetric nucleophilic addition/alkylation of secondary phosphine oxides. A series of tertiary phosphine oxides were generated with up to 99 % yield and 99.5 % ee, and with broad functional-group tolerance. Mechanistic studies reveal that (R)-secondary phosphine oxides preferentially interact with the cobalt catalysts to produce P-stereogenic compounds.
- Cheng, An-Qi,Duan, Wei-Liang,Wang, Huai-Yu,Wang, Tao,Wei, Li-Hua,Wu, Zeng-Hua,Yang, Huai-Lan,Yuan, Meng,Zhang, Zunting,Zhao, Ya-Xuan
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p. 27241 - 27246
(2021/11/27)
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- Synthesis of P-chiral, non-racemic phosphinylacetates via enzymatic resolution of racemates
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A series of racemic methyl phosphinylacetates was hydrolyzed in the presence of porcine liver esterase (PLE) under the kinetic resolution conditions to give the corresponding P-chiral phosphinylacetic acids and recovered esters in high enantiomeric purity (72-100% ee). The Jones' active site model was applied to explain the enantioselectivity of this reaction.
- Kielbasinski,Zurawinski,Pietrusiewicz,Zablocka,Mikolajczyk
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p. 564 - 572
(2007/10/03)
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- Enzymatic Resolution of Racemic Phosphinoylacetates Having a Stereogenic Phosphorus Atom
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A series of racemic methyl alkylphenylphosphinoylacetates was hydrolyzed in the presence of pig liver esterase (PLE) to give the corresponding P-chiral phosphinoylacetic acids and unreacted esters in a high enantiomeric purity (72-100percent ee).
- Kielbasinski, Piotr,Zurawinski, Remigiusz,Pietrusiewicz, K. Michal,Zablocka, Maria,Mikolajczyk, Marian
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p. 7081 - 7084
(2007/10/02)
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- STEREOSPECIFIC REDUCTION OF DIASTEREOMERICALLY PURE MENTHYL PHOSPHINATES: A NEW ROUTE TO OPTICALLY ACTIVE PHOSPHINE OXIDES
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Diastereomerically pure menthyl phosphinates are stereospecifically reduced by lithium 4,4'-di-tert-butylbiphenylide.Subsequent treatment with alkyl halides affords phosphine oxides with high optical purity.
- Koide, Yasuhiro,Sakamoto, Atsushi,Imamoto, Tsuneo
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p. 3375 - 3376
(2007/10/02)
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- Asymmetric synthesis of phosphinates, phosphine oxides and phosphines by Michaelis Arbuzov rearrangement of chiral oxazaphospholidine
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A general approach to asymmetric synthesis of high optically active tertiary organophosphorus compounds is described.Oxazaphospholidine 3 reacts with alkyl halide to give regio and stereoselectively the corresponding phosphinamide 4.Methyl phenyl phosphin
- Juge, S.,Genet, J. P.
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p. 2783 - 2786
(2007/10/02)
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- Optically Active Phosphines. Facile Preparation of the Optically Active n-Propylmethylbenzyl- and Methylphenylbenzylphosphine Oxides as Precursors to the Corresponding Tertiary Phosphines
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The optically active phosphine oxides MePhP(O)CH2Ph (6) and n-PrMeP(O)CH2Ph (9) are readily prepared by a new route from the easily available, essentially optically pure, O-isopropyl S-alkyl methylphosphonothioates 4 and 7.Two successive Grignard reactions give 6 in 52-55percent and 9 in 18-24percent overall chemical yields.Reductions of 6 and 9 with PhSiH3 afford the corresponding optically active phosphines MePhCH2Ph (1) and n-PrMePCH2Ph (2) of optical purities (45-70percent and 53-57percent, respectively) which are quite suitable for studies of the stereochemistries of reactions occurring at phosphorus.The relative ease of the procedure and the fact that both enantiomers are equally readily available especially recommend this route for the preperation of 1.Moreover, no other experimentally detailed, published method for the preparation of an optically active trialkylphosphine such as 2 in reasonably high optical purity is available.The route to phosphine 1 depends on the use of potentially tridentate ligand (SCH2CH2OCH2CH2OCH2CH3) on phosphorus which activates 4 toward reaction with PhMgBr and also allows CH3CH2OCH2CH2OCH2CH2 to be selectively displaced.Quite surprisingly, this displacement occurs with inversion of configuration at phosphorus by contrast to the retentive stereochemistry normally observed on reaction of O-alkyl S-alkyl methylphosphonothioates with Grignards.Evidence is also presented for the potential generality of this method for the preparation of optically active dialkylphenyl- and trialkylphosphines.
- Moriyama, Masaru,Bentrude, Wesley G.
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p. 4727 - 4733
(2007/10/02)
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- PHOSPHORORGANISCHE VERBINDUNGEN 103. Die ozonolytische Desulfurierung von Thiophosphorylverbindungen: P=S -> P=O
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The sulfur atom in thiophosphorylgroups P=S is exchanged by oxygen with retention of configuration according to (1) and (2) as a result of an interaction of the P=S groups with ozone (Table 1 and 2).In dithiophosphinicacidesters only the thionosulfur is easily replaced by oxygen using ozone.The absolute configuration of the enantiomeric methyl-phenyl-phosphinicacid-p-nitrophenylesters 7 an 8 is controlled on the basis of the reaction circle (4).Serine enzymes are blocked by the phosphinicacidesters 7 and 8 by a rate factor of about 60 faster than by the corresponding thionophosphinicacidesters 5 and 6.The phosphinicacidesters 7 (and 8) have a high O-selectivity in competing reactions (7:n-BuOH:n-BuNH2 = 1:1:1) in contrast to the thionophosphinicacidesters 5 (and 6) with no selectivity (ester:amide = 4:6).
- Horner, L.,Flemming, H. W.
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p. 245 - 252
(2007/10/02)
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- PREPARATION OF OPTICALLY ACTIVE PHOSPHINE OXIDES BY REGIOSELECTIVE CLEAVAGE OF CYCLIC PHENYLPHOSPHONITE WITH ALKYL HALIDES
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The Arbuzov reaction of (2S,4S)-methyl-2-phenyl-1,3,2-dioxaphosphorinane with various alkyl halides gave the diastereomerically pure phosphinates with regioselective cleavage of the primary carbon-oxygen bond.These phosphinates reacted with Grignard reage
- Segi, Masahito,Nakamura, Yoshiyuki,Nakajima, Tadashi,Suga, Sohei
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p. 913 - 916
(2007/10/02)
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